// @name      The Fade Anything Technique
// @namespace http://www.axentric.com/aside/fat/
// @version   1.0-RC1
// @author    Adam Michela

var Fat = {
   make_hex : function (r,g,b)
   {
      r = r.toString(16); if (r.length == 1) r = '0' + r;
      g = g.toString(16); if (g.length == 1) g = '0' + g;
      b = b.toString(16); if (b.length == 1) b = '0' + b;
      return "#" + r + g + b;
   },
   fade_all : function ()
   {
      var a = document.getElementsByTagName("*");
      for (var i = 0; i < a.length; i++)
      {
         var o = a[i];
         var r = /fade-?(\w{3,6})?/.exec(o.className);
         if (r)
         {
            if (!r[1]) r[1] = "";
            if (o.id) Fat.fade_element(o.id,null,null,"#"+r[1]);
         }
      }
   },
   fade_element : function (id, fps, duration, from, to)
   {
      if (!fps) fps = 30;
      if (!duration) duration = 3000;
      if (!from || from=="#") from = "#FFFF33";
      if (!to) to = this.get_bgcolor(id);

      var frames = Math.round(fps * (duration / 1000));
      var interval = duration / frames;
      var delay = interval;
      var frame = 0;

      if (from.length < 7) from += from.substr(1,3);
      if (to.length < 7) to += to.substr(1,3);

      var rf = parseInt(from.substr(1,2),16);
      var gf = parseInt(from.substr(3,2),16);
      var bf = parseInt(from.substr(5,2),16);
      var rt = parseInt(to.substr(1,2),16);
      var gt = parseInt(to.substr(3,2),16);
      var bt = parseInt(to.substr(5,2),16);

      var r,g,b,h;
      while (frame < frames)
      {
         r = Math.floor(rf * ((frames-frame)/frames) + rt * (frame/frames));
         g = Math.floor(gf * ((frames-frame)/frames) + gt * (frame/frames));
         b = Math.floor(bf * ((frames-frame)/frames) + bt * (frame/frames));
         h = this.make_hex(r,g,b);

         setTimeout("Fat.set_bgcolor('"+id+"','"+h+"')", delay);

         frame++;
         delay = interval * frame;
      }
      setTimeout("Fat.set_bgcolor('"+id+"','"+to+"')", delay);
   },
   set_bgcolor : function (id, c)
   {
      var o = document.getElementById(id);
      o.style.backgroundColor = c;
   },
   get_bgcolor : function (id)
   {
      var o = document.getElementById(id);
      while(o)
      {
         var c;
         if (window.getComputedStyle) c = window.getComputedStyle(o,null).getPropertyValue("background-color");
         if (o.currentStyle) c = o.currentStyle.backgroundColor;
         if ((c != "" && c != "transparent") || o.tagName == "BODY") { break; }
         o = o.parentNode;
      }
      if (c == undefined || c == "" || c == "transparent") c = "#FFFFFF";
      var rgb = c.match(/rgb\s*\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})\s*\)/);
      if (rgb) c = this.make_hex(parseInt(rgb[1]),parseInt(rgb[2]),parseInt(rgb[3]));
      return c;
   }
}

window.onload = function ()
   {
   Fat.fade_all();
   }